| | | Linn County | IA | 19113 | | Cedar Rapids, IA 16300 | Cedar Rapids-Iowa City,
IA 168 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=LinnCounty+IA |
| | | Madison County | IA | 19121 | | Des Moines-West Des
Moines, IA 19780 | Des Moines-West Des
Moines-Ames, IA 218 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=MadisonCounty+IA |
| | | Mills County | IA | 19129 | | Omaha, NE-IA 36540 | Omaha-Fremont, NE-IA 420 | Outlying | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=MillsCounty+IA |
| | | Plymouth County | IA | 19149 | | Le Mars, IA 30180 | Sioux City-Le Mars,
IA-NE-SD 512 | Central | metro county (urban) | manufacturing-dependent | https://maps.google.com/?q=PlymouthCounty+IA |
| | | Polk County | IA | 19153 | | Des Moines-West Des
Moines, IA 19780 | Des Moines-West Des
Moines-Ames, IA 218 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=PolkCounty+IA |
| | | Pottawattamie County | IA | 19155 | | Omaha, NE-IA 36540 | Omaha-Fremont, NE-IA 420 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=PottawattamieCounty+IA |
| | | Scott County | IA | 19163 | | Davenport-Moline-Rock
Island, IA-IL 19340 | Davenport-Moline, IA-IL 209 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=ScottCounty+IA |
| | | Story County | IA | 19169 | | Ames, IA 11180 | Des Moines-West Des
Moines-Ames, IA 218 | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=StoryCounty+IA |
| | | Warren County | IA | 19181 | | Des Moines-West Des
Moines, IA 19780 | Des Moines-West Des
Moines-Ames, IA 218 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=WarrenCounty+IA |
| | | Washington County | IA | 19183 | | Iowa City, IA 26980 | Cedar Rapids-Iowa City,
IA 168 | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=WashingtonCounty+IA |
